The official Symantec Security Advisory can be found here:
https://www.symantec.com/security_response/securityupdates/detail.jsp?fid=security_advisory&pvid=security_advisory&year=&suid=20171120_00

Questions have come into support looking for clairification on what versions are effected and if there are any plans for updates to versions prior to ITMS 8.1 RU4. Support is awaiting further information at this time.

However the official release states "versions prior to 8.1 RU4", until further clairification please read that as all versions prior (7.5, 7.6, 8.0, and 8.1).

Currently the path to mitigate the vulnerability is to upgrade to 8.1 RU4 (or later when availalbe).